Unexpected token < in JSON at position 4
Question
var url="http://fsa.citop.in/lnct/service/signProcess.aspx";
var data={txtLogId: "abc@xyz.com",txtLogPass: "xyz",hdnReqType2: "sign87162"};
var success=function(data, textStatus, jqXHR) {
console.log(data);
};
var fail=function(jqXHR, textStatus, errorThrown) {
console.log("Error:" + errorThrown );
}
$.ajax({
type: "POST",
url: url,
data:data,
success:success,
error:fail,
});
This POST request gives me the error, SyntaxError: Unexpected token < in JSON at position 4 , in the console of the page ' http://fsa.citop.in/lnct/ ' in chrome.
But if I use fsa.citop.in/lnct/service/signProcess.aspx (ie no http://), it gives me no error, but nothing comes back in data. On success of POST request, a JSON object is expected. Please somebody explain what is happening here and how it could be resolved.
2 answers
solution1
14 2016-12-22 10:15:35
For those who encounter this problem in AWS Lambda code editor it is most likely your session has timed out.
Try reloading the page and signing in again. It should resolve this.
solution2
13 ACCPTED 2016-04-23 18:26:12
It's most likely because the response is HTML and it's trying to parse it as something else. The < at position 4 is the first < of <!DOCTYPE html... .
You should try to specify dataType in your ajax call (see http://api.jquery.com/jquery.ajax/ ) and also make signProcess.aspx to return something more useful (currently the response content type is application/json but it prints HTML).
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